Application note-A novel, low-cost pH-controlled solenoid-based CO2 dosing device for microalgal and cyanobacterial cultivation systems

This application note proposes a novel, low-cost, pH-controlled solenoid-based CO2 dosing device for microalgal and cyanobacterial cultivation systems. The device consists of an Arduino-Uno microcontroller, a (ph-4502c) module, a pH probe, a micro-SD card for data logging, and a relay-controlled solenoid valve. C functions are used to control, and data log the pH and operate the solenoid valve for CO2 dosing in microalgal cultivation systems. With open-source programming, the device can be used for a wide range of applications in both industry and academia. The proposed device is flexible, customizable, and upgradable. This study aims to develop a low-cost pH-controlled, solenoid-based CO2 dosing and data logging device and utilize it for pH control and CO2 dosing in a 200 L outdoor raceway tanks utilized in cultivating and studying the growth of marine cyanobacterium Geitlerinema sp. and Spirulina sp.